The invention relates to a method for authenticating a vehicle-external device in a bus system of a motor vehicle comprising control units.
In order to prevent the sequence control system, which is stored in control units, or the corresponding software, which is executed by one or more of the processors, provided in the control units, from being manipulated, it is important to monitor the authorization of the access to the control units. The authorization may be verified by cryptographic measures.
Execution of the corresponding cryptographic measures stresses the processor(s) of the control unit and other hardware components of the control unit or requires more powerful and, thus, more expensive control units. The more powerful control units may be required in a control unit that is used millions of times, as in the case of the control unit of a motor vehicle.
Exemplary embodiments of the present invention provide a method that effectively and inexpensively prevents a sequence control system, which is stored in a control unit, from being manipulated.
Other objects, advantages and novel features of the present invention will become apparent from the following detailed description of the invention when considered in conjunction with the accompanying drawings.